import type { FormEvent } from 'react';
import { useState } from 'react';
import { useQuery, useQueryClient } from '@tanstack/react-query';
import { toast } from 'sonner';
import { useFormat } from 'i18n';
import { useTranslation } from '@/lib/i18n';
import { Copy, Ban, Plus, KeyRound, Loader2, Trash2 } from 'lucide-react';
import { useClient } from 'hooks/useClient';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Button } from '@/components/ui/button';
import { copyToClipboard } from 'helpers/clipboard';

// Your own API keys: one per app or device, so a phone holds a credential you can revoke on its own
// instead of a session everything shares.
//
// The key is returned by POST and never again — the column holds a SHA-256, so there is nothing to read
// back. That drives the whole screen: the new key sits in a panel that stays put until dismissed, because
// the moment it disappears the only remedy is to revoke and mint another. Same reasoning as the DAV app
// passwords beside this.
//
// A key carries your full account authority. It is not more than you already had — it is what your
// password could already do — but it does mean a leaked key is a leaked account, so revoke is one click
// and "last used" is on every row: a key that has never been used is the tell that something was set up
// wrong, and one used from somewhere you did not expect is the tell that matters more.

type ApiKey = {
  id: number;
  name: string;
  prefix: string;
  lastUsedAt: string | null;
  expiresAt: string | null;
  revokedAt: string | null;
  createdAt: string;
};

type Minted = { key: string; name: string };

const API_KEYS_QUERY_KEY = ['API_KEYS'];

// `toLocaleDateString(undefined, …)` followed the BROWSER's locale, so a Portuguese UI showed the
// browser's dates. `useFormat` binds it to the locale the rest of the app is in (D7).

export const ApiKeys = () => {
  const { t } = useTranslation();
  const { date: formatDate } = useFormat();

  const copy = async (text: string) => {
    try {
      await copyToClipboard(text);
      toast.success(t('settings.profile.apiKeys.copied'));
    } catch {
      toast.error(t('settings.profile.apiKeys.copyFailed'));
    }
  };

  const client = useClient();
  const queryClient = useQueryClient();
  const [name, setName] = useState('');
  const [isCreating, setIsCreating] = useState(false);
  const [showRevoked, setShowRevoked] = useState(false);
  const [minted, setMinted] = useState<Minted | null>(null);

  const { data, isLoading } = useQuery<{ keys: ApiKey[] }>({
    queryKey: API_KEYS_QUERY_KEY,
    queryFn: () => client.get<{ keys: ApiKey[] }>('/api-keys'),
  });

  const refresh = () => queryClient.invalidateQueries({ queryKey: API_KEYS_QUERY_KEY });

  const create = async (ev?: FormEvent) => {
    ev?.preventDefault();
    const trimmed = name.trim();
    if (!trimmed || isCreating) return;
    setIsCreating(true);
    try {
      const res = await client.post<{ key: string }>('/api-keys', { name: trimmed });
      setMinted({ key: res.key, name: trimmed });
      setName('');
      await refresh();
    } catch (ex) {
      toast.error(ex instanceof Error ? ex.message : t('settings.profile.apiKeys.createFailed'));
    } finally {
      setIsCreating(false);
    }
  };

  const forget = async (id: number) => {
    try {
      await client.delete(`/api-keys/${id}/record`);
      await refresh();
    } catch {
      toast.error(t('settings.profile.apiKeys.forgetFailed'));
    }
  };

  const revoke = async (id: number) => {
    try {
      await client.delete(`/api-keys/${id}`);
      toast.success(t('settings.profile.apiKeys.revokeDone'));
      await refresh();
    } catch {
      toast.error(t('settings.profile.apiKeys.revokeFailed'));
    }
  };

  const allKeys = data?.keys ?? [];

  // Dead means revoked OR past its expiry — the same test the row rendering uses, lifted here so the
  // count in the toggle and the rows it reveals can never disagree.
  const isDead = (entry: ApiKey) =>
    !!entry.revokedAt || (!!entry.expiresAt && new Date(entry.expiresAt).getTime() <= Date.now());

  // Dead keys are HIDDEN by default rather than merely dimmed. Revoking is the normal end of a key's
  // life, so on any account that has been used for a while the dead ones outnumber the live ones and the
  // screen stops answering the question it exists for — which of my keys still work. The rows are kept
  // and reachable; they are just not the first thing shown.
  const deadKeys = allKeys.filter(isDead);
  const keys = showRevoked ? allKeys : allKeys.filter((entry) => !isDead(entry));

  if (isLoading) {
    return (
      <div className="flex items-center gap-2 p-6 text-sm text-muted-foreground">
        <Loader2 className="h-4 w-4 animate-spin" /> {t('settings.profile.apiKeys.loading')}
      </div>
    );
  }

  return (
    <div className="grid gap-5">
      <p className="text-sm text-duck-dark/70 dark:text-foreground/70">
        {t('settings.profile.apiKeys.intro')} <code className="font-mono text-xs">Authorization: Bearer …</code>.
      </p>

      {minted && (
        <div className="grid gap-3 rounded-lg border-2 border-duck-teal/40 bg-duck-teal/5 p-4">
          <div className="text-sm font-medium text-duck-dark dark:text-foreground">
            {t('settings.profile.apiKeys.mintedTitle', { name: minted.name })}
          </div>
          <p className="text-xs text-duck-dark/60 dark:text-foreground/60">
            This is the only time it is displayed. It's stored hashed, so it can't be shown again — if you lose it,
            revoke this entry and make another.
          </p>

          <div className="flex items-center gap-2">
            <code className="min-w-0 flex-1 truncate rounded bg-background/70 px-2 py-1.5 font-mono text-xs">
              {minted.key}
            </code>
            <Button
              variant="ghost"
              size="sm"
              onClick={() => copy(minted.key)}
              title={t('settings.profile.apiKeys.copyKey')}
            >
              <Copy className="h-3.5 w-3.5" />
            </Button>
          </div>

          <Button variant="outline" size="sm" className="justify-self-start" onClick={() => setMinted(null)}>
            {t('settings.profile.apiKeys.savedIt')}
          </Button>
        </div>
      )}

      <form onSubmit={create} className="flex items-end gap-2">
        <Label className="grid flex-1 gap-2">
          <span className="text-duck-dark/70 dark:text-foreground/70">{t('settings.profile.apiKeys.newKey')}</span>
          <Input
            className="h-11 bg-background/60 border-duck-dark/20"
            value={name}
            onChange={(ev) => setName(ev.target.value)}
            placeholder={t('settings.profile.apiKeys.namePlaceholder')}
          />
        </Label>
        <Button type="submit" disabled={!name.trim() || isCreating} className="h-11">
          <Plus className="me-1.5 h-4 w-4" />
          {t('settings.profile.apiKeys.create')}
        </Button>
      </form>

      {keys.length === 0 ? (
        <div className="rounded-lg border border-dashed border-duck-dark/15 dark:border-foreground/15 p-6 text-center text-sm text-duck-dark/40 dark:text-foreground/40">
          {/* "No keys yet" would be false on an account whose keys are all revoked, and it is the sentence
              that would send somebody looking for a bug in the list. */}
          {allKeys.length === 0 ? t('settings.profile.apiKeys.noneYet') : t('settings.profile.apiKeys.noneInUse')}
        </div>
      ) : (
        <div className="grid gap-2">
          {keys.map((entry) => {
            const expired = !!entry.expiresAt && new Date(entry.expiresAt).getTime() <= Date.now();
            const dead = !!entry.revokedAt || expired;
            const lastUsed = entry.lastUsedAt
              ? formatDate(entry.lastUsedAt, { month: 'short', day: 'numeric', year: 'numeric' })
              : null;
            return (
              <div
                key={entry.id}
                className={`flex items-center gap-3 rounded-lg border p-3 ${
                  dead
                    ? 'border-duck-dark/10 dark:border-foreground/10 opacity-50'
                    : 'border-duck-dark/15 dark:border-foreground/15'
                }`}
              >
                <KeyRound className="h-4 w-4 shrink-0 text-duck-teal/70" />
                <div className="min-w-0 flex-1">
                  <div className="truncate text-sm text-duck-dark dark:text-foreground">
                    {entry.name}
                    {entry.revokedAt && (
                      <span className="ms-2 text-xs text-red-500">{t('settings.profile.apiKeys.revoked')}</span>
                    )}
                    {!entry.revokedAt && expired && (
                      <span className="ms-2 text-xs text-red-500">{t('settings.profile.apiKeys.expired')}</span>
                    )}
                  </div>
                  <div className="text-xs text-duck-dark/40 dark:text-foreground/40">
                    <code className="font-mono">{entry.prefix}…</code>
                    {' · '}
                    {/* "never used" is the tell that an app was configured wrong, so it earns its own wording. */}
                    {lastUsed
                      ? t('settings.profile.apiKeys.lastUsed', { date: lastUsed })
                      : t('settings.profile.apiKeys.neverUsed')}
                  </div>
                </div>
                {dead ? (
                  // Only offered once the key is already dead — the server refuses it otherwise, and the
                  // button matching that rule is what keeps the two from drifting.
                  <Button
                    variant="ghost"
                    size="sm"
                    onClick={() => void forget(entry.id)}
                    title={t('settings.profile.apiKeys.forget')}
                    className="hover:text-red-500"
                  >
                    <Trash2 className="h-3.5 w-3.5" />
                  </Button>
                ) : (
                  <Button
                    variant="ghost"
                    size="sm"
                    onClick={() => void revoke(entry.id)}
                    title={t('settings.profile.apiKeys.revoke')}
                    className="hover:text-red-500"
                  >
                    <Ban className="h-3.5 w-3.5" />
                  </Button>
                )}
              </div>
            );
          })}
        </div>
      )}

      {deadKeys.length > 0 && (
        <button
          type="button"
          onClick={() => setShowRevoked((v) => !v)}
          className="mt-3 cursor-pointer text-xs text-duck-dark/40 underline underline-offset-2 transition-colors hover:text-duck-dark/70 dark:text-foreground/40 dark:hover:text-foreground/70"
        >
          {showRevoked
            ? t('settings.profile.apiKeys.hideDead')
            : t('settings.profile.apiKeys.showDead', { count: deadKeys.length })}
        </button>
      )}
    </div>
  );
};